The interaction between sigma70 and the beta-flap of Escherichia coli RNA polymerase inhibits extension of nascent RNA during early elongation.

ABSTRACT: The sigma-subunit of bacterial RNA polymerase (RNAP) is required for promoter-specific transcription initiation. This function depends on specific intersubunit interactions that occur when sigma associates with the RNAP core enzyme to form RNAP holoenzyme. Among these interactions, that between conserved region 4 of sigma and the flap domain of the RNAP beta-subunit (beta-flap) is critical for recognition of the major class of bacterial promoters. Here, we describe the isolation of amino acid substitutions in region 4 of Escherichia coli sigma(70) that have specific effects on the sigma(70) region 4/beta-flap interaction, either weakening or strengthening it. Using these sigma(70) mutants, we demonstrate that the sigma region 4/beta-flap interaction also can affect events occurring downstr

SUBMITTER: Nickels BE 

PROVIDER: S-EPMC555512 | biostudies-literature | 2005 Mar

REPOSITORIES: biostudies-literature